Thursday, March 12, 2009

Mobile beep for emergency Cell Broadcast

Can you set a mobile phone to beep when an emergency "Cell Broadcast" is received? I will be presenting a seminar on a "National Bushfire Warning System" in Canberra, 16 April 2009. One option I discuss in this will be to use "Cell Broadcast" to mobile phones for an Australian Community Warning System. This would have the advantage that a short text message could be set to all the phones in a small area or the whole country in a few seconds.

Last week the Victorian Government tried to send an SMS message about bush-fires to all mobile phone users in the state. The message was sent 2 Mar 2009 14:30:10. It took approximately one hour to send. Also some people in Victoria did not get the message and some not in Victoria did.

Cell Broadcast is designed for simultaneous delivery of messages to multiple users in a specified area. It is more formally known as "Short Message Service - Cell Broadcast" (SMS-CB) to distinguish it from the popular SMS, more formally: Short Message Service - Point to Point (SMS-PP). Use of cell broadcast would overcome the problem of the speed of dispatch of messages and misdirection. Cell Broadcast messages are designed to send to all handsets in one or more cells at once. This speeds up transmission and removes the need to have a list of the phones to send to.

However, one problem with Cell Broadcasts is that mobile phones usually have the alert (tone or vibration) turned off. Some phones may have no way to turn on alert for Cell Broadcasts and others may have no way to turn it on just for emergency messages. Does anyone have experience with using Cell Broadcast with particular model phones?

The details of cell broadcast for emergencies is discussed in "Support for Cell Broadcast as Global Emergency Alert System" by Karin Axelsson and Cynthia Novak (Linköpings University, 2007). The authors point out that different phones handle Cell Broadcast differently and the phone makers call the service by different names.

The Cell Broadcast Forum have a Handset Requirements Specification (October 2006). This has a section on "Requirements on Handling of Emergency Messages" which requires the phone to alert for an emergency message, even if the user has switched off alerts for messages. However, this requirement does not seem to be followed by manufacturers:
2.10 Requirements on Handling of Emergency Messages

This section deals with the handling by the ME when an emergency warning message is received. This section does not so much provide the Cell Broadcast forum’s view on handling of Emergency Warning Messages, but the requirements of the Dutch government, that may become applicable throughout the EU in due time.

2.10.1 Mandatory Requirements

58. Factory setting: In a country where a public warning service over Cell Broadcast is operational, the government, or the operators may require that the default Factory Setting be set to active, i.e. CB messages can be received and the Message Identifier that has been assigned to the public warning service be selected.

59. Reception tone: The ME shall indicate the reception of an
emergency message by playing a ring tone that is specific for
emergency messages and cannot be allocated to other services on the ME. This ringtone shall be activated even if the ME setting is set to silent mode, meeting mode, buzzing mode, etc., and also regardless of the Display Mode (Normal or Direct).

60. Storage: Emergency messages shall always be stored, unless or until the user decides to delete the message.

2.10.2 Other Requirements

61. The WARN Act that was effectuated in the US in October 2006 states that it shall be impossible to opt-out of a presidential level message. Further recommendations or legislation were not available at the time of writing of this section and will be included at a later stage (2007). ...

From: Handset Requirements Specification , The Cell Broadcast Forum, October 2006
David Crowe gives a good overview of Cell Broadcast for Emergency Alerts in Wireless Telecom Magazine Q3‘2006. He points out limitations, including messages being even shorter than SMS (in 88 character segments), no verification a message was received and no standard categories to identify emergency messages and standard no user interface. One issue he raises is the detrimental impact of cell broadcast on battery life. However, Axelsson and Novak's research indicates this is not a problem. As Crowenotes, a conservative approach would be to use this for single segment (88 characters) short messages, as was used with SMS in Victoria. The message would just advise of the emergency andto check with other services, such as ABC Radio.

Nokia's Extended User Guide for the N85 phone gives Cell broadcast settings. It is likely that newer large screen "smart phones" will better support cell broadcast. As an example Blackberry provide details on how to Turn on cell broadcasting. It should also be possible to add this feature to later model phones with a software upgrade over the air.

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